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प्रश्न
Out of NaCl and AgCl, which one shows Frenkel defect and why?
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उत्तर
The Frenkel defect is that in which one smaller ion (usually cations) move from its lattice position to an interstitial site i.e. a tetrahedral octahedral hole to form a vacancy in the lattice. Of course, AgCl has the defect because the size of AgCl is intermediate and since the size of Ag+ cation is smaller than chloride ion so it can move to interstitial spaces causing Frenkel to defect while in NaCl (alkali metal halide) they have a larger size of cations which do not fit into voids and so the defect is not shown by the alkali metal halides.
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संबंधित प्रश्न
What type of defect is shown by NaCl in
stoichiometric defects, and
Ionic solids containing large differences in sizes of ions show ____________.
Point defect is also known as ____________.
Alkali halids do not show Frenkel defect because ____________.
Which of the following crystals does not exhibit Frenkel defect?
Cations are present in the interstitial sites in ______.
Which of the following point defects are shown by AgBr(s) crystals?
- Schottky defect
- Frenkel defect
- Metal excess defect
- Metal deficiency defect
Which of the following statements are not true?
(i) Vacancy defect results in a decrease in the density of the substance.
(ii) Interstitial defects results in an increase in the density of the substance.
(iii) Impurity defect has no effect on the density of the substance.
(iv) Frankel defect results in an increase in the density of the substance.
Match the defects given in Column I with the statements in given Column II.
| Column I | Column II |
| (i) Simple vacancy defect | (a) shown by non-ionic solids and increases density of the solid. |
| (ii) Simple interstitial defect | (b) shown by ionic solids and decreases density of the solid. |
| (iii) Frenkel defect | (c) shown by non ionic solids and density of the solid decreases. |
| (iv) Schottky defect | (d) shown by ionic solids and density of the solid remains the same. |
Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion: In any ionic solid (MX) with Schottky defects, the number of positive and negative ions are same.
Reason: Equal number of cation and anion vacancies are present.
